摘要
针对亚硫酸盐体系镀金液的稳定性和镀层均匀性问题,制定了测试评估方法及工艺改进方案。提出了高温稳定性测试、Ni^(2+)耐受能力测试和还原剂稳定性测试3种方法来评价镀金液稳定性。镀层均匀性则通过测厚仪多点测厚,计算总体相对标准偏差(RSD)进行表征。通过单因素试验对配位剂组成和工艺条件进行了优化,得到置换镀金的最佳镀液组成和工艺条件为:Na_3Au(SO_3)_25 mmol/L,Na_2SO_3 0.3 mol/L,三乙醇胺0.1 mol/L,Na_2S_2O_3 5 mmol/L,Na_2HPO_4 0.2 mol/L,pH 6.5,温度60°C,搅拌速率1 m/min。优化后的镀液稳定,施镀10 min所得镀层的平均厚度约为0.05μm,RSD小于10%,表面粗糙度为20.8 nm左右,满足化学镀镍/置换镀金(ENIG)工艺的要求。
Aiming at the problems of stability of sulfite-based bath for immersion gold plating and uniformity of coating, some test methods and process improvements were taken. High temperature stability test, Ni2＋ tolerance test and reductant stability test were proposed to evaluate the bath stability. The uniformity of coating thickness were characterized by calculating the relative standard deviation （RSD） of coating thickness at different positions tested using a thickness gauge. The optimal bath composition and process conditions for immersion gold plating through optimizing the complexant composition and process conditions by single factor experiment are as follows： Na3Au（SO3）2 5 mmol/L, Na2SO3 0.3 mol/L, triethanolamine 0.1 mol/L, Na2S203 5 mmot/L, Na2HPO4 0.2 mol/L, pH 6.5, temperature 60 ℃ and stirring rate 1 m/min. The comprehensive performance of the coating deposited from the given bath for 10 min meets the requirements of electroless nickel/immersion gold （ENIG） process, as shown by an average thickness of ca.0.05 μm （with a RSD below 10%） and a surface roughness of ca.20.8 nm.
出处
《电镀与涂饰》
CAS
CSCD
北大核心
2016年第9期444-448,共5页
Electroplating & Finishing
关键词
化学镀镍
置换镀金
亚硫酸盐
配位剂
厚度均匀性
镀液稳定性
测定
electroless nickel plating, immersion gold plating
sulfite
complexant
thickness uniformity
bath stability
determination
